Lewis Hamilton endured a difficult afternoon in the Mercedes at the Monaco Grand Prix

Hamilton had set the fastest ever time during a Monaco Grand Prix race weekend in the morning as the faster 2017 F1 cars ripped up the record books.

However, struggles set in after lunch as the Brit complained over the radion of being unable to get heat into the tyres while F1 World Drivers' Championship leader Sebastian Vettel was the first man into the 1min12s, leading the field by nearly half a second.

Pirelli had initially nominated the minimum tyre pressures as 19 psi and 18 psi on the front and rear tyres respectively, but lowered that yesterday to 17 and 16.5.

The Ferrari car is understood to be better at heating up the tyres at lower pressures while Hamilton complained over team radio about struggling to get them up to temperature, a problem confirmed by team-mate Valtteri Bottas.